Table of Contents:

The Mediator Guide


0.4 - 2016-11-09


If you have a Mediator, or know about them, and either disagree with something in this guide, or have some extra information you'd like to add, please do contact us. We want this document to grow to cover as much detail about Mediators as possible!

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A nicely formatted PDF version is available from:

The source of the project lives at:

You are very welcome to file bugs there, or submit pull requests, but if you do not want to do either of those, please feel free to email the current maintainer (listed above) with your corrections/suggestions/etc. If you want to become an active author of the document, you are very welcome to join our GitHub team and work directly on the document.

There are threads on the main Amiga forums for any discussions you want to have about the guide:

You can also discuss the guide on the Amiga-Mediator Yahoo Group


To write this guide, we have drawn extensively on the help and writings of other people. Specific thanks to:


This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

1. Introduction

Created by Elbox, the Mediators are a range of PCI/Zorro busboards for Amiga computers. They allow users to install industry-standard PCI cards into their Amigas.

There exist Mediators for:

Various models and revisions of Mediators have existed since their initial release in 2000/2001. The authors of this guide do not have access to every variant of Mediator, so for now the information contained here can only be assumed to be related to the following models:

2. Hardware

A Mediator typically consists of two main parts:

The backplane board is generally very simple, it is really just a series of PCI and/or Zorro slots. The real magic of the Mediator happens on the bridge board. This board sits on both PCI and Zorro buses, and contains a series of chips (known as MACH) that translate between the protocols of PCI and Zorro, allowing the Amiga to communicate with the PCI cards and vice versa.

2.1 Supported PCI cards

There are drivers for a number of PCI cards, with most of the drivers being maintained by Elbox. Unfortunately the Driver Development Kit for writing additional drivers is not freely available, limiting the possibilities for community maintained drivers.

Elbox maintains a list of compatible cards on their website

There are also one or two additional drivers on Aminet

2.1.1 Supported voltages

All Mediators support 5V PCI cards, but only some support 3.3V PCI cards. You can usually tell which voltages a PCI card works with, by looking at its edge connector. If it has a section cut out of the edge connector 5.6cm away from the backplate, it requires 3.3V. If it has a section cut out of the edge connector 10cm from the backplate, it requires 5V. Cards that have both sections cut out, work with either 3.3V or 5V. Some users have noticed that some PCI cards appear to be 5V compatible, but actually do require 3.3V.

It is possible to modify 5V Mediators to supply 3.3V to cards that need it, by connecting a 3.3V supply to the appropriate PCI pins on the back of the Mediator busboard.
(If you would like to document the process here, please contact us!)

It is also often possible to modify PCI cards to have their own voltage regulator (e.g. LM1084) to convert 5V to 3.3V on the card itself.

2.1.2 IRQs

PCI cards generally need to have an IRQ allocated to them to be able to function correctly, and while sharing IRQs is possible, not all cards are happy with it. Mediator bridgeboards supply and configure 5 IRQs. While this is not normally a problem (particularly if you have fewer than 5 PCI slots on your Mediator), if you are having stability issues where usage of one card seems to affect another, check the output of C:PCIInfo and look for any IRQ sharing. If you do find one or more IRQs being shared, the only way to resolve stability is to re-order your PCI cards.

2.2 Installation

Obviously the installation for different Amigas varies widely, because of their different form factors. Specific information for various models can be found below, but the general steps are:

NOTE: Some users have reported that on some Mediators, the order of PCI cards is important, particularly the placement of the graphics card. Please contact us if you know more about this.

2.2.1 4000Di

2.3 Configuration

In terms of hardware configuration, Mediators generally have very little that needs to be done. They have a few jumpers and that's it. However, these jumpers are generally not documented well, and vary between models.

2.3.1 4000Di

This model has three jumpers:

3. Software

Along with the hardware, Elbox also produces software and drivers for Mediators and the PCI cards they are compatible with. This is supplied with the Mediator and is called the Mediator Multimedia CD (generally known as MMCD). It is only relevant to AmigaOS 3.1/3.5/3.9 - 4.1 uses its own drivers.

NOTE: It's quite common for the CD supplied by Elbox to be significantly out of date, so always check their website for a driver pack update (MM_CD_UP). However, even these update packs do not always contain the most recently available drivers/libraries. The same download page also lists individual updates that have been released (e.g. pci.library) and the dates. Ensure you have the latest versions of everything.

3.1 Installation

The Elbox installers are not particularly neat in their choices of where to install the software/drivers. If you are feeling particularly confident, you may choose to install the various components by hand, but we would suggest that at least your first time, you may want to use the Elbox installers:

3.1.1 General

Somewhat unusually for Amiga hardware, there is no device driver for the Mediator, instead, access to the PCI cards happens through pci.library. Once you have installed the drivers, open a shell and run C:PCIInfo and you should see a listing of any PCI cards you have installed (which ideally should just be the graphics card at this point).

NOTE: A graphics card is generally vital to the operation of a Mediator because of the RAM it provides. PCI cards are unable to access the Amiga's memory through the Zorro bus, so the Mediator drivers reserve a portion of the graphics card's memory for DMA operations with other cards. Thus, any card you install, which uses DMA (i.e. most cards), will only operate if there is a graphics card present.

FURTHER NOTE: The mere presence of a graphics card is not sufficient, Picasso96 must also be installed and configured to use the appropriate driver for your PCI graphics card. You don't have to be using an RTG screenmode through the graphics card, but without it at least having an active entry in DEVS:Monitors/ most other PCI operations will not be possible.

3.1.2 Graphics card

NOTE: These instructions are kept intentionally simple. For Radeon/Voodoo users, there are good installation guides in the MMCD/MM_CD_UP.


3.1.3 Sound card

Assuming you ran the Elbox installer, it will have installed AHI, the Amiga's retargetable audio framework, several drivers, and a Mixer application. The Elbox installer appears to install a strange mixture of different versions of AHI, but only two files are specific to the hardware, so you can start with a stock install of AHI and add in the .card and audiomode files from Elbox, that apply to your soundcard (so either sb128 or fm801). Some users seem to find that AHI 5.6 is more stable than AHI 6.0.

Your sound card will require some additional configuration:

NOTE: AHI is exposed to applications as a series of units. Each unit can be configured to send its audio to a soundcard of your choice, with quality settings of your choosing. For this section we will assume that you only have one soundcard, you will configure all your applications to use AHI unit 0, and you want the highest possible sound quality.

NOTE: The Mixer app supplied by Elbox is not very high quality (Elbox themselves recommend using a third party mixer). A good alternative is GhostMix. You will need to remove the Elbox mixer item in S:User-Startup to use a different mixer application.

FURTHER NOTE: GhostMix does not create the required directory for its preferences. Either run the Elbox mixer once and Save the settings, or manually create a directory ENVARC:Mediator/Mixer/

3.1.4 Network card

There are Mediator drivers for two Realtek chipsets, 8029 (10Mb/s) via MediatorNET.device and 8139 (100Mb/s) via FastEthernet.device. To use one of these, you'll need a TCP/IP stack installed, such as:

Of these, Roadshow is the newest and is often the fastest. The choice is yours, and configuring the stack is beyond the scope of this document.

There is an environment variable for RTL-8139 devices, ENVARC:Mediator/FastEthernet which controls how the Ethernet link should be configured, see Section 3.2 for more information.

With a good network card in a well configured system, it should be possible to achieve roughly 1MB/s through the network interface.

3.1.5 USB card

The only USB card that can currently be used in a Mediator, is Elbox's Spider card (which is actually an NEC card with modified firmware). Installation is very simple:


3.1.6 TV Tuners

Please contribute to this section if you have any useful information :)

3.1.7 SCSI cards

There is a driver on Aminet that allows you to use certain Adaptec SCSI cards from the AHA-2940UW range. Depending on your card's connectors, you will be able to attach up to 14 SCSI devices to the various SCSI connectors on the card (usually 50pin internal, 68pin internal and 68pin external, of which any two can be in use at the same time).

NOTE: Even though these cards are capable of high speed data transfer (around 40MB/s), in a Mediator they are limited by the overheads of being moving data from the SCSI card to graphics card RAM, and from there across the Zorro3 bus to the Amiga's CPU (and vice versa). This means that SCSI devices attached to the Adaptec card will actually only operate at around 3MB/s (i.e. roughly equivalent to the A1200/A4000 internal IDE).

3.1.8 Serial/Parallel cards

Please contribute to this section if you have any useful information :)

3.1.9 MPEG 2 decoder cards

Drivers for these cards have never been released.

3.2 Configuration

3.2.1 Environment Variables

There are many Mediator environment variables which can be set in ENVARC:Mediator/:

3.3 Versions

Here we attempt to collect a definitive list of Mediator software versions. If you have any MMCD or MM_CD_UP versions not included here, please contact us :)
Most of the MM_CD_UP archives can be downloaded from Elbox's website, and many of them are included on the latest MMCD CDs.

3.3.1 MMCD

The earliest version of MMCD that the authors currently have access to, is 2.0. The driver versions on this CD are the same as those shown in MM_CD_UP 2.0c below.

3.3.2 MM_CD_UP

NOTE: Bold indicates a version was updated. N/A indicates the file was not included.

File 2.5 2.4 2.3 2.2 2.1 2.0c 1.31 1.28 1.26
C/SBMixer 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4
C/TV 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 4.14 4.14 4.14 4.14 4.14 4.14 4.12 4.10 4.5 4.20 4.20 4.20 4.20 4.20 4.20 4.18 4.16 4.11
FastEthernet.device 1.25 1.25 1.25 1.25 1.25 1.24 1.21 1.20 1.15
MediatorNET.device 2.10 2.10 2.10 2.10 2.10 2.10 N/A N/A N/A
mixer.library 1.11 1.11 1.11 1.11 1.11 1.11 1.10 1.10 1.9
pci.library 9.11 9.11 9.10 9.9 9.7 9.4 N/A N/A N/A
Radeon.card 2.23 2.22 2.20 2.19 2.12 2.12 1.7 1.0 N/A
Virge.card 1.13 1.13 1.13 1.13 1.13 1.12 N/A N/A N/A
Voodoo.card 4.35 4.34 4.34 4.30 4.30 4.30 4.28 4.27 4.23
tv.library 4.13 4.13 4.13 4.13 4.13 4.13 4.9 4.6 4.0
tv.vhi 1.5 1.5 1.5 1.5 1.5 1.5 1.4 1.4 1.3

3.3.3 Spider II Driver

This driver is distributed separately from MMCD, although spider.device 3.20 appeared in MM_CD_UP 2.0c.

The Spider II USB 2.0 CD includes spider.device 3.22.

3.3.4 pci.library

At the time of writing, the latest version of pci.library (11.0) is distribtued separately from MM_CD_UP, and must be downloaded directly from Elbox's website.

4. Troubleshooting

Mediators are extremely complex pieces of hardware and driver development tends to be very slow, so it's possible to run into various issues, both hardware and software.

4.1 Hardware

4.1.1 Mediator disappears from Autoconfig after a few reboots

Your Mediator is defective and needs to be returned to Elbox for repair/replacement. There have been multiple reports that the 2016 A4000 "Black" version of the Mediator has been unreliable resulting in the Mediator disappearing after a reboot or crashing when the graphics driver is loaded.

4.2 Software

4.2.1 Guru meditations from ramlib (80000004)

This seems to be a widely experienced symptom, and may trace back to multiple underlying causes. Potential remedies worth investigating: